Hydrophilic dye intermediates



Patented June 14, 1949 HYDROPHILIC DYE INTEBMEDIATES David WillcoxWoodward, Wilmington, Del., as-

signor to E. I. du Pont de Nemonrs & Company, Wilmington, Del., acorporation of Delaware No Drawing. Application February 8, 1945, SerialNo. 576,906

7 Claims. (Cl. 260-473) This invention relates to colloid dyeintermediates. More particularly, it relates to hydrophilic polymericcolloid dye intermediates which are useful in processes of colorphotography. Still more particularly, the invention relates to ethers ofhydrolyzed olefin/vinyl ester interpolymers wherein the componentsattached by an ether linkage to the polymer chain contain dyeintermediate nuclei.

An object of this invention is to provide new and useful polymeric dyeintermediates. A still further object is to provide such materials whichcan be used alone as dispersing and binding agents for light-sensitivesilver salts.

The above objects can be attained by the. preparation oi dyeintermediate ethers of hydrolyzed terminally unsaturatedmonoolefin/vinyl ester inter-polymers. The ethers have two chemicallyjoined components, one of which consists of a polymer chain and theother consists of a pinrality oi dye intermediate components having thegeneral iormula RA-- wherein R is a group containing a dye-formingnucleus and A is a divalent saturated aliphatic nucleus whose freevalence stems from a methylene or substituted methylene group and islinked through an ether oxygen atom to a carbon atom of the polymerchain. In the resulting products, the dye intermediate nuclei are anintegral part of the polymer molecule, 1. e., the products are chemicalentities and not physical mixtures of polymers and simple monomeric dyeintermediates and hence there is no diiliculty arising from difierencesin solubilities and compatibilities of the components.

This application is a continuation-in-part of Woodward United Statesapplication Serial No. 528,946, filed March Si, 19%, now Patent No.2,il5,381.

These hydrophilic dye intermediate ethers can be prepared byetherification of the hydrolyzed olefin/vinyl ester interpolymers withdye intermediate components containing a reactive group attached to anon-aromatic hydrocarbon group, e. g.. a methylene group. Such reactivegroups are hydroxyl or halogen, e. g., chlorine, bromine and iodine.Alternatively, the dye intermediate component can be joined by use of abifunctional connecting agent such as an aidehyde, e. g., acetaldehyde,benzaldehyde, formaldehyde or materials which release formaldehyde orreact like formaldehyde. The dye intermediate components are added insuch amounts that a plurality of ether groups are present in eachmolecule of the final hydrophilic dye intermediate polymer.

By dye intermediates or color-formers are meant nuclei containing groupswhich are capable of coupling with the oxidation products of colorcoupling aromatic primary amino developing agents formed on developmentof silver salt images to form a quinoneimine (including indamine,indoaniline and indophenol) dye or an azomethine dye. These dyeintermediate nuclei are also capable of coupling with diazotizedaromatic amines to form azo dyes.

Nuclei of the above type are well-known in the dye art and colorphotography art. They are sometimes called color-formers, couplingcomponents, etc.

These dye intermediate nuclei have as the active coupling groups astructure which may be represented as wherein X is H0 or RHN, where R ishydrogen or an alkyl radical, which may be substituted, e. g., methyl,ethyl, hydroxyethyl, B-chlorethyl, benzyl, dodecyl, etc., and n is 0or 1. This group is found in the reactive methylene dye intermediatesand in aromatic hydroxyl and amino compounds and includes the reactiveethenol, aminoethenyl, il-hydroxyand l-amino-L3- butadienyl groups.These groups occur in phenols, naphthols, anilines, naphthylamines,acylacetamides, cyanoacetamides, beta-ketoesters, pyrazolones,homophthalimides, coumaranones, indoxyls, thloindoxyls, etc.

The reactive ethenol group represented by Ho-( J=cH- v occurs in phenolsand naphthols which couple in the ortho position and in the alkalisoluble or enol form of most reactive methylene dye intermediates. Thesereactive methylene groups have a hydrogen rendered mobile by theproximity of certain unsaturated groups such as for example o=o, ('J=N-,-o

and others. The -CH: group is usually present between two such groups,for, example,

in a cyclic or acyclic system.

The reactive aminoethenyl group,

occurs in aromatic amino compounds which couple in the ortho position.

The 4-hydroxyand 4-amino-l,3-butadienyl groups represented as occur inphenolic, naphtholic and aromatic amino compounds which couple in thepara position.

In all of these dye intermediate groups the hydrogen atoms in thecoupling reactive position may be replaced by groups readily eliminatedin the coupling reaction, e. g., halogen, sulfonic acid, carboxylicacid, etc.

The preferred compounds are color-forming ethers of hydrolyzedethylene/vinyl acetate interpolymers of a mol ratio of 0.2 to 0.02 ofethylene to one of vinyl acetate, in which the color-former nuclei arejoined to the interpolymer chain through a CH2O group. These compoundscan be advantageously prepared by reacting formaldehyde or aformaldehyde-yielding material in a solution or suspension of thehydrolyzed ethylene/vinyl acetate interpolymer and color former in thepresence of a condensation catalyst. The reaction may be carried outsimultaneously or stepwise. For example, formaldehyde may be reacted-with such hydrolyzed ethylene/vinyl acetate interpolymer to form amethylol derivative which may then be condensed with the color-formingcompound or pref erably the formaldehyde may be condensed with thecolor-forming compound and the resulting methylol derivative condensedwith the aforedescribed hydrolyzed interpolymers. The resultingcompounds may be represented by the general formula:

wherein the carbon atoms of the respective units form a chain of carbonatoms in the polymeric molecule, R is a dye intermediate nucleus aspreviously defined, n is at least 100, m is not more than 0.212 and :cis Anon to lion.

In the previous formula the chain nucleus is that obtained from thehydrolysis products from the ethylene/vinyl acetate interpolymers. Thehydrolysis products are substantially free from acetate groups and areinterpolymers of the formu a in which n is at least 100 and m is lessthan 0.2 n. Hydroxyl polymers of the aforedescribed type suitable foruse in preparing the novel hydrophilic polymeric dye intermediate ethersof this invention may be prepared from the polymers described incopending application Serial No. 446,116, filed June 6, 1942, nowabandoned. They are obtained by the interpolymerization of vinyl estersand ethylene to yield an interpolymer having less than 0.2 mol of olefinto 1 vinyl ester, followed by partial or complete hydrolysis.

Hydrolysis or alcoholysis of the ethylene/vinyl ester interpolymers ispreferably carried out by dissolving the interpolymer in an alcohol suchas methanol or ethanol, or in a mixture of an alcohol and a hydrocarbonsuch as toluene, and then treating with a suitable hydrolyzing agent orcatalyst such as alkali, e. g., NaOH, KOH, or mineral acid, e. g., HCl,H2804, etc. The hydrolysis may be partial or complete, depending 4 onthe nature of the solvent. the amount and kind of catalyst used, and thetime and temperature of reaction. The following general principlesapply: (1) the greater the amount of vinyl ester in the interpolymer,the more rapid the rate of hydrolysis; (2) alkaline hydrolyzing agentsgive more rapid rates of hydrolysis than mineral acid catalysts.

The term hydrolysis" as used herein and in the accompanying claims isintended to include alcoholysis as well as hydrolysis with the use ofwater. Regardless of whether water or an alcohol is used to split offthe ester groups in the interpolymer, the product is the same.

Complete hydrolysis can be obtained in most cases by dissolving theinterpolymer in alcohol or alcohol-toluene to give about a 10%-.solution, adding an excess of sodium or potassium hydroxide in alcoholand refluxing for about one hour.

The hydroxyl polymers containing (CHzM where 11:2 to 4 groups attachedto groups, may be modified, if desired, by further reaction to introduceminor portions of other groups, e. g., acetal, ester, ether groups, etc.However, all of the products useful in preparing the color-formingethers of the present invention have the group CH2--CHOH- representingat least 50% of the polymer chain, 1. e., for every chain atoms thereare at least 25 hydroxyl groups. Further, it is preferred that the finalcolor-forming ethers themselves contain at least 12.5 hydroxyl groupsfor every 100 chain atoms, and that the polymer consists of at least 25%(CH2CHOH) groups so that they will have the desiredpermeability-solubility characteristics as herein defined. It is alsopreferred that between 1. and 30 color-forming ether groups shall bepresent for each 100 chain atoms. The color-forming compounds are highlypolymeric (by this is meant having a p lymer chain in excess of 200carbon atoms) and strong unsupported films may be formed from them. Theyhave a high softening point. The preferred dye intermediate polymericethers are not dissolved by cold water (20 C.) but are soluble to theextent of at least 5 parts in 100 parts of boiling water or a boilingmixture of water containing not more than 50% of a water-miscibleorganic solvent, and preferably not more than 25% of ethanol.

The above limitations enable the compounds to fulfill the rigorousphysical demands required of dispersing and binding agents used inpreparing light-sensitive silver salt layers of photographic elements.The novel hydrophilic polymeric color formers possess a uniquecombination of properties among which may be mentioned (1) ability toform a strong coherent unsupported film, (2) ready permeability to waterand photographic processing solutions at temperatures in theneighborhood of 20 C., (3) insolubility and freedom from softening inwater at moderate temperatures, (4) transparency and freedom from color,(5) adequate solubility in satisfactory solvents for coating, (6)freedom from adverse action on sensitive silver salts, (7) a relativelyhigh softening point, (8) ability to disperse, prevent coagulation, andsedimentation of silver salts.

The hydrophilic polymer ether color formers of the present invention,when associated with light-sensitive silver halides, combine not onlythe above properties but, in addition, function as -with 1000 parts ofacetone and filtered.

chromogens. In fact, the number of color-coupling groups in the polymercan be controlled so.

group in controlled amounts usually reduces the water solubilitysomewhat. However, if the colorforming group contains a solubilizinggroup, the solubility of the final product may be increased slightly. Itis often satisfactory merely to balance the dye intermediate ethergroups and hydroxyl groups in the correct ratio to obtain the idealpermeability and film properties. If in any one polymer the color-formersubstitution which gives the optimum color or chromogenic developmentdoes not yield the desired solubility, this is corrected by theintroduction of other groups such as acetal, ether, or ester groupsdesigned to have the proper solubilizing or insolubilizing edect. Forinstance, acetal formation with benzaldehyde decreases water solubilitywhile with o-sulfobenzaldehyde water solubility is increased.

The invention will be further illustrated but is not intended to belimited by the following examples.

Example I A mixture of 100 parts of o-hydroxybenzyl drolyzedethylene/vinyl acetate polymer of mol ratio 0.07 of ethylene to 1.0 ofvinyl acetate, 400 parts of dioxane and 2 parts of 85% phosphoric acidis stirred at 80 C. for 6 hours, then diluted The solid material isextracted for 12 hours with acetone, then dried to give 114 g. of awhite, hydrophilic color-forming polymer having the following probablecolor unit structure:

The gain in weight indicates a substitution of about 0% of the hydroxylgroup, i. e., about out of every 100 chain atoms contain a colorforminggroup Example II A solution of 200 parts of phenol and 400 parts ofsodium hydroxide is cooled to 15 C. and mixed with 60 parts of 37%Formalin solution and let stand at C. for 60 hours. The solu- 'tion isthen almost neutralized by adding 100 parts of concentrated sulfuricacid, the mixture being kept at 20 C. by addition of ice. The phenoliccompounds are teparated from the aqueous fraction by extraction withether. The ether extracts after washing and drying are evaporated underreduced pressure at 20 C. and added to a mixture of 100 parts ofhydrolyzed ethylene/ vinyl acetate polymer of mol ratio about 0.05 ofethylene to l of vinyl acetate and 300 parts of dioxane containing 5parts of 85% phosphoric acid. The mixture is stirred for six hours at 80C. diluted with l000 parts of acetone, filtered and extracted withacetone for 12 hours to yield 120 parts of a white powder soluble inboiling l0-50% ethanol. This product is an o-hydroxybenzyl ether of thesame general structure as the product of Example I.

Example III A mixture of 15 parts of hydrolyzed ethylene/vinyl acetatinterpolymer of about 3 to 4% ethylene content by weight, 30 parts of2-hydroxy-3-methyl-5-chlorobenzyl alcohol (prepared from formaldehydeand p-chloro-o-cresol), 80 parts of dioxane and 2 parts of 85%phosphoric acid are stirred at 80 C. for 2 hours, then 5 parts of aceticanhydride is added and the stirring continued for 1 hour at 80 C. Theproduct, a polymeric 2-hydroxy-3-methyl-5-chlorobenzyl ether, is washedand extracted with aceton and dried.

Example IV In a preparation similar to that recorded under Example II,250 parts of o-phenylphenol is used in place of the phenol. Ten parts ofthe resulting white polymer, a 5% substituted 2-hydroxy- 3-phenylbenzylether of the hydrolyzed ethylene/vinyl acetate polymer is dissolved in amixture of parts of water and 50 parts of ethanol at 80 C. 4

Example V acetone, filtered, and extracted with acetone.

The product is a mixed (l-hydroxy-Z-naphthyl) methylether/benzaldehyde-osulfonic acid acetal of a hydrolzed ethylene/vindacetate interpolymer. It yields bright blue dye images upon colorcoupling development of silver halide images with p-aminodiethylaniline.

Example VI A mixture of 22 parts of hydrolyzed ethylene/vinyl acetatepolymer of the type specified in Example V, 30 parts ofo-sulfobenzaldehyde, 100 parts of dioxane, and 2 parts of 85% phosphoricacid was stirred at 80 C. for hour. Then a mixture of 45 parts ofphenylmethylpyrazolone and 7 parts of paraformaldehyde preheated to C.is added and the mixture stirred for 2 hours at C., then washed withacetone and extracted. The resulting, light tan powder, namely,

the mixed (ii-methyl-1-phenyl- 5-pyrazolone-4- yllmethylether/benzaldehyde-o-sulfonic acid acetal of hydrolyzed ethylene/ vinylacetate interpolymer, is soluble in hot 20% ethanol. It yields brilliantmagenta dye images upon color coupling development of silver halideimages with p-aminodiethylaniline.

. Example VII A mixture of 56 parts ofv o-chloroacetoacetanilide. 50parts of 37% Formalin solution, parts of 50% alcohol, and 2 parts ofconcen-' product, a polymeric ether of the following probable color unitstructure:

O in

is washed and extracted with acetone and dried to give 25.5 parts of a.white powder soluble in boiling water. It yielded a yellow dye imageupon color coupling development of silver halide images withp-aminodiethylaniline.

Example VIII A solution of 25 parts of methyl chioromethyl ether in 60parts of dioxane is added slowly to a suspension of 40 parts of sodiumacetoacetanilide in 150 parts of dioxane. The mixture is stirred 15minutes and filtered. The filtrate is diluted with 750 parts of waterand allowed to stand for one hour. The precipitate is filtered, washedwith water, dried, dissolved in 25 parts of dioxane, and added to amixture of 22 parts of hydrolyzed ethylene/vinyl acetate polymer of thetype specifled in Example VIII, 125 parts of dioxane, and 1 part of 85%phosphoric acid. The mixture is stirred for six hours, diluted withacetone, filtered, and extracted with acetone. The resulting polymer issimilar in structure to that of Example VII and yields a yellow dyeimage upon color coupling development of silver salt images withp-aminodiethylaniline.

Example IX A mixture of 28 parts of N-phenyiacetoacetanilide, 3 parts ofparaformaldehyde, 135 parts of dioxane is heated at 80 C. for one hourthen diluted with 300 cc. of water and extracted twice with ether. Theether solution is dried filtered, and evaporated to about 25 parts, thendissolved in 50 parts of dioxane. This dioxane solution is added to amixture of 20 parts of hydrolyzed ethylene/vinyl acetate polymer of molratio about 0.07 of ethylene to 1 of vinyl acetate, 1 part of 85%phosphoric acid, and 150 parts of dioxane. The mixture is heated threehours at 75-80 0., washed several times with acetone, and extracted.This material is a partially substituted polymeric ether containing thefollowing probable color unit structure:

In place of any of the specific hydrophilic color-forming ethersemployed in the above examples there may be used other color-couplingethers of hydrolyzed olefin/vinyl esters which have similar physicalproperties. Since different color-forming groups have different effectson the solubility and permeability, it is often necessary, in order tosecure the desired properties, to employ hydrophilic hydroxyl polymers(i. e., hydrolyzed olefin/vinyl esters) of different viscositiesanddifferent solubilities. If a product is obtained which is toosoluble, a higher viscosity material or one containing more olefin maybe used, but if the color-forming polymer is slightly too insoluble orimpermeable, a lower viscosity polymer or one containing less olefinshould be employed. Other useful methods of controlling the solubilityand permeability include the substitution of a part of the hydroxylgroups of the hydroxyl polymer with. for instance, ester, acetal, orether groups. of acetate groups increases the water solubility whilelarger amounts decrease the water solubility. Acetal groups decreasewater solubility I and increase the solubility in organic solvents orsolvent-water mixtures. To secure a greater insolubilizing efiect, asmall percentage of aromatic ester or acetal groups may be introduced.For example, if the final color-forming binding agent is too soluble,one of the following derivatives can be employed: An ethylene/vinylacetate interpolymer of 0.05 to 0.2 mol ratio, (1) 60 to 75% hydrolyzed,(2) hydrolyzed which has been not more than 20% acetalized withbutyraldehyde, (3) 100% hydrolyzed followed by 10% or lessesterification with benzoic acid, (4) 100% hydrolyzed and approximately5% acetalized with benzaldehyde or (5) completely hydrolyzed followed byesterification with not more than 10% butyric ester groups. Suchsubstitution can, of course, be introduced prior or subsequent tocondensation of the colorformer with the interpolymer. If, on the otherhand, a greater solubilizin effect is desired, acidic salt-forminggroups, e. g., sulfonic or carboxylic acid groups can be introducedeither on the color-forming nucleus or by acetal formation with aldehydeacids, by partial esterification with dibasic acids or by etherformation with hydroxyacids, etc. For example, if the color-formingbinding agent is too low in solubility one of the following derivativescan be employed: (1) a completely hydrolyzed ethylene/vinyl acetateinterpolymer of 0.02-

to 0.1 moi ratio of ethylene to 1 of vinyl acetate up to 20% acetalizedwith phthalaldehydic acid, benzaldehyde ortho-sulfonic acid, glyoxylicacid, etc., (2) having on 20% or less of the hydroxyl group half estersof phthalic, succinic, etc. acids, (3) 20% or less etherified withglycolic acid. Such groups also can be introduced either before or aftercondensation of the color former with the polymer.

The preferred reaction for preparing these new color-formin bindingagents involves 1 ether formation through formaldehyde to give acompound having each of the color-forming nuclei attached through amethylene group to an ether oxygen which is in turn attached to a carbonof the linear carbon chain of the polymer.

The color-forming nuclei need not, however, be attached directly to themethylene ether group. Non-color-forming formaldehyde reactive groups,e. g., amide, mercapto, or aliphatic amino or hydroxyl may be present inthe dye former and react with the formaldehyde to form methylolderivatives capable of condensing with the hydroxyl groups of thepolymer to form ethers.

Alternatively, other etherification methods may be employed. In all ofthese compounds a bifunctional non-color-coupling radical may intervenebetween the ether methylene groups and the color coupling nuclei.

Thus, the color-forming nuclei can be joined to the polymer chainthrough other ether groups such as 0CH2COX, --OCH2CH2X, -OCHRX, 0CR2X,-ocfncmsx,

-ocHocH:cox, -OCH2CHOHCHzOX OCH2OCH2X,OCH2CH2NHX -ocmcnoncmmrx, etc..wherein the R The presence of a minor portion I groups are hydrogen orsmall alkyl radicals and X is a color-forming group as herein describedby the following representative methods: (1) The hydrolyzed olefin/vinylester interpolymer is stirred or milled with 10 to 20% aqueous sodiumhydroxide and a color-former containing an aliphatic chloride, bromideor iodide group is added and the mixture stirred and warmed to split outhydrogen halide from the reactants thus connecting the color-formingnuclei to the polymer chain through an ether linkage, (2) a, partialglycolic acid other is formed by reaction of the hydrophilic polymerwith chloroacetic acid and. sodium hydroxide after which the carboxylicacid groups are converted to amides by reaction with color-formingcompounds containing amino groups or (3) by reduction of nitrobenzylethers of hydrolyzed olefin/vinyl ester interpolymers followed byreaction with color-former acid chlorides.

In addition to the ether color-forming groups of the above examples,many of the other welllmown color-coupling components may be employed.Thus, the dye intermediate nucleus may be any phenol, naphthol oraromatic amine having a coupling position available ortho or para to thearomatic hydroxyl or amine group or any active methylene compound, i.e., a compound having a CH2- group activated by two unsaturated groupstaken from the class of --CONH-, COalkyl, C0Oaryl, N=C, connected eitherdirectly or through a conjugated system. Such active methylene compoundsare distinguished by their ability to enolize in alkaline solutionforming a soluble alkali metal salt and include many acyclic andheterocyclic compounds known in the art. Examples of such activemethylene compounds include (1) betaketoacylamldes of the typeRCOCI-IzCONHR'; where R is a hydrocarbon or heterocyclic radical and Ris preferably aromatic, e. g., benzoylacetanilide, furoylacetanilide,p-acetoacetamidobenzoic acid, naphthoylacetanilide, p-nitroacetanilide,2.5 dichloroacetoacetanilide, (2) pyrazolones, e. g.,l-p-carboxyphenyl-3-methyl-5-pyrazclone,1-phenyl-3-carboxy-5-pyrazolone, l-pchlorophenyl-3-methyl-5-pyrazolone,l-m-sulfophenyl-3-phenyl-5-pyrazolone, (3) benzyl cyanides, e. g.,p-nitrobenzylcyanide, (4) indoxyl and thioindoxyl, (5) homophthalimides,e. g., N- phenylhomophthalimide, N-beta-naphthylhomophthalimide,N-dodecylhomophthalimide, (6) 2,4-dlhydroxyquinoline, (7)diketohydrindene, (8) malonamides,, e. g., N,N'-diphenylmalonamide,ethyl N-phenylmalonamate, (9) phenacylpyridinium halides, (10)hydroxypyridines, (ll) cyanacetanilide, (l2) benzoylacetonitrile, (13)ethyl cyanoacetate, etc.

In the method of preparing these polymeric color-forming binding agentsemploying formaldehyde to connect the color-former to the hydroxylpolymer chain, the formaldehyde may be in any form. Thus, it can be usedas solid paraformaldehyde or dissolved or suspended in water or solventsfor the color former, or there may also be used formaldehyde-releasingcompounds. such as trioxan, hexamethylenetetramine, methylene diacetate,or compounds capable of forming methylol derivatives, e. g.,chloromethyl ether, etc.

Alternatively, dimethylol derivatives of amides, ureas, etc., e. g.,dimethylolurea, dimethyloladip- 10 amide, dimethyloloxamide and theirethers such as bis-methoxymethylurea may be used in place offormaldehyde for linking the dye intermediates to the polymer chain.

The term hydrophilic" as used in this application and claims, whenreferring to the dye intermediates, etc.. is intended to denotecompounds which in the form of thin layers, e. g., one to ten microns inthickness are insoluble in water at C. but are freely water permeable.

The preferred embodiment of the invention contemplates the use of colorformers derived from interpolymers of vinyl acetate with less than 0.2mol (less than 12% by weight) of ethylene per mol of vinyl acetatebecause of their superior film properties. However, other aliphaticterminally unsaturated mono-oleflns also are useful in preparing theproducts of this invention. The limitation to aliphatic terminallyunsaturated monoolefins is made on the basis of ease of preparation ofsatisfactory polymers in good yield. Thus, the purely aliphatic olefinsinterpolymerize with vinyl esters in contrast to a non-aliphaticoleflnic compound such as styrene which, as is wellknown, inhibitspolymerization of the vinyl esters. Similarly, it has been found thatthe terminally unsaturated olefins enter into the copolymeriza- .tionmore readily than such olefins as butene-Z,

the terminal carbon atoms of which are saturated. Mono-oleflns areutilized exclusively because it has been found diflicult to obtainstable, soluble interpolymers from vinyl esters and dior polyolefins.Because of their availability and because they have been found to enterinto the copolymerization readily the aliphatic terminally unsaturatedmono-olefins containing less than 5 carbon atoms are preferred. Theinterpolymers containing an olefin/vinyl ester mol ratio of 0.2 to 0.02are best suited for use in preparing the products of this invention.When the olefin contains less than 5 carbon atoms this corresponds to anolefin content of 20% or less by weight. Any hydrolyzable polymerizablevinyl ester can be used as far as is known. The vinyl esters of thelower fatty acids such as vinyl acetate or vinyl propionate arepreferred by virtue of their availability, ease of copolymerization andlow cost.

The new color forming hydrophilic polymeric ethers of this invention areespecially useful in the preparation of dye images utilizingphotographic developing agents which couple therewith. They may bedissolved in water or watersolvent mixtures and incorporated in gelatinsilver halide emulsions. The new color formers being themselves bindingagents and highly polymeric do.not wash out of or migrate in a gelatinemulsion during a photographic process. The color formers may be used asthe sole binding agents for light-sensitive silver salts and are usefulas layers in photographic elements.

These new hydrophilic polymeric ether dye intermediates are alsotusefulin many other dyeing operations. Thus they may be incorporated inpolymers or polymer solutions used for spinning fibers or casting films,e. g., cellulose, cellulose esters and ethers, nylons, polyesters, vinylpolymers, etc. Fibers or films prepared from these compositions may bedyed by treatment with solutions of diazotized amines or othercolorforming reagents. Dyes formed in fibers and films in this way arean integral part of the article and show outstanding wash-fastness,being completely unaffected by dry cleaning or prolonged and repeatedwashing in strong soap 11 solutions. Other important uses include theimpregnation of fabrics with the dye intermediates followed by treatmentwith formaldehyde and baking to insolubilize them, after which they maybe treated with diazotized amines to form azo dyes. Alternatively, theintermediates may be converted to dyes first, then dyed onto fabrics andgiven special after-treatments, e. g., baking with formaldehyde or otherbi-functional insolubilizing or cross-linking agents. Dyed articlesformed in this way also exhibit superior resistance to washing,laundering, and dry cleaning.

I claim:

1. A color former consisting of a hydrophilic ether of a hydrolyzedaliphatic mono-olefin/vinyl ester interpolymer having a plurality ofcolor former nuclei each nucleus being attached to the chain atoms ofsaid interpolymer through a CH:O- linkage, said nuclei possessing astructure of the formula:

x m where X is a member of the group consisting of HO- and primary andsecondary amino radicals and n is a number from the group consisting ofand 1, said olefin being an aliphatic terminally unsaturated mono-olefinof less than five carbon atoms.

2. A hydrophilic color former comprising a hydrolyzed aliphaticmono-olefin/vinyl acetate interpolymer having a plurality of colorformer nuclei, each nucleus being connected through a CH2-O- linkage toa carbon atom in the chain of atoms of said polymer, said nucleipossessing a structure of the formula:

where X is a member of the group consisting of HO- and primary andsecondary amino radicals and n is a number from the group consisting of0 and 1, said olefin being an aliphatic terminally unsaturatedmono-olefin of less than five carbon atoms, said interpolymer containingat least 12.5 but less than 49 hydroxyl groups for every 100 chainatoms, between 1 and color-forming ether groups for each 100 chainatoms, and a polymer chain in excess of 200 carbon atoms.

3. A color former comprising a. hydrophilic polyether of a hydrolyzedethylene/vinyl acetate interpolymer of mol ratio of 0.2 to 0.02 ofethylene to 1 of vinyl acetate, having a plurality of color formernuclei nucleus being connected through a CH20 linkage to chain carbonatoms of said interpolymer, said nuclei possessing a structure of theformula:

where X is a member of the group consisting of HO- and primary andsecondary amino radicals and n is a number from the group consisting of0 and 1, said interpolymer containing at least 12.5 but less than 49hydroxyl groups for every 100 chain atoms, between 1 and 30color-forming ether groups for each 100 chain atoms, and a polymer chainin excess of 200 carbon atoms.

4. A process which comprises condensing a color former possessing acolor-yielding structure of the formula:

where X is a member of the group consisting of HO- and primary andsecondary amino radicals and n is a number from the group consisting of0 and 1, with formaldehyde at a temperature of 25 to C. in the presenceof an acid catalyst and a hydrophillc hydrolyzed ethylene/vinyl acetateinterpolymer of mol ratio of 0.2 to 0.02 of ethylene to 1 of vinylacetate and containing 12.5 hydroxyl groups for every chain atoms,between 1 and 30 color-forming ether groups for each 100 chain atoms,and a polymer chain in excess of 200 carbon atoms, said formaldehydebeing present in an amount sufllcient to introduce 12.5 to 49 colorformer nuclei per 100 hydroxyl groups.

5. A hydrophilic polymeric ether of 2-hydroxy- 3-methyl-5-chlorobenzylalcohol of a hydrolyzed ethylene/vinyl acetate interpolymer of mol ratioof 0.2 to 0.02 of ethylene to 1 of vinyl acetate, said ether containingrecurring units of the formula:

said interpolymer containing at least 12.5 but less than 49 hydroxylgroups for every 100 chain atoms, between 1 and 30 of the 2-hydroxy-3-methyl-5-chlorobenzy1 groups for each 100 chain atoms, and a polymerchain in excess of 200 carbon atoms.

6. A hydrophilic polymeric ether of 2-hydroxy 3-phenylbenzyl alcohol ofa hydrolyzed ethylene/ vinyl acetate interpolymer of mol ratio of 0.2 to0.02 of ethylene to 1 of vinyl acetate, said ether containing recurringunits of the formula:

-cIn-cnsaid interpolymer containing at least 12.5 but less than 49hydroxyl groups for every 100 chain atoms, between 1 and Y30 of the2-hydroxy-3- phenylbenzyl ether groups for each 100 chain atoms, and apolymer chain in excessof 200 carbon atoms.

7. A hydrophilic 'polymeric ether of a 2-hydroxy-benzyl alcohol of ahydrolyzed ethylene/ vinyl acetate interpolymer of mol ratio of 0.2 to0.03 of ethylene to 1 of vinyl acetate, said ether containing recurringunits of the formula:

(kHz-R where R is an ortho-hydroxybenzene nucleus, said interpolymercontaining at least 12.5 but less than 49 hydroxyl groups for every 100chain atoms, between 1 and 30 of the ortho-hydroxybenzene groups foreach 100 chain atoms, and a polymer chain in excess of 200 carbon atoms.

DAVID WILLCOX WOODWARD.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS

